1. Field of the Invention:
The present invention relates to the field of turbo-compressor air supply systems and, more particularly, to an apparatus for cooling a bearing mounted around a shaft of the turbo-compressor.
2. Description of the Prior Art:
There are presently available industrial spray painting systems in which a turbo-compressor and its associated drive motor are mounted upon a cart so that the unit may be moved about within the plant to the article to be painted.
In units of this type, the motor and turbo-compressor typically are mounted side by side upon a horizontal plate which constitutes the top of the cart with the motor shaft and turbine shaft extending vertically downwardly through their housings and the mounting plate to be coupled to each other by a drive belt located below the mounting plate. Typically, a box-like chamber is provided at the underside of the mounting plate to enclose the shafts and drive belt which are driven at relatively high speed.
In the usual case, the turbo-compressor also includes bearings which are mounted around the turbine shaft at upper and lower locations thereon. Due to the high speed of rotation of the turbine shaft, a great deal of heat is generated. Conventionally, both the upper and lower turbine shaft bearings are located inside the housing which covers the turbo-compressor. Because of this confinement inside the turbo-compressor housing, the heat in the immediate environment of the turbine shaft bearings does not become dissipated and can build up to high levels. For example, it has been found that the operating temperature in the vicinity of the upper turbine shaft bearing can reach 207.degree. F. or higher. Temperatures of this level often exceed the performance specifications of the bearing and, hence, contribute to premature bearing failure.
Obviously, it would be highly desirable if a turbo-compressor of the type described were designed with provisions made for a cooler operating environment for the upper turbine shaft bearing. The present invention is especially directed to an apparatus for cooling the shaft bearing adapted for use in the system described above.